Volumes on London Benchmark Are 'Dropping Like a Stone'

Investors are shunning the main benchmark for global currencies amid a widespread probe into possible manipulation of foreign-exchange markets, according to several people who attended a high-level committee of currency-market participants that met in London this week.

Trading volumes at the 4 p.m. WM/Reuters fix "are dropping like a stone," said one participant at the foreign-exchange committee of financial-markets...